1. Field of the Invention
The present invention relates to a recording tape cartridge in which a single reel is accommodated within a case, and a recording tape, such as a magnetic tape or the like, which is used as a recording/playback medium of mainly a computer or the like, is wound on the reel.
2. Description of the Related Art
Conventionally, magnetic tape cartridges have been known in which a magnetic tape, which is used as a data recording/playback medium of a computer or the like, is wound on a single reel, and the reel is accommodated within a case. A leader member, which is a leader pin, a leader tape, or a leader block, for example, is provided at the distal end of the magnetic tape. A pull-out means provided at a drive device pulls out the leader member from an opening of the magnetic tape cartridge, and the magnetic tape fixed to the leader member is wound onto a take-up reel of the drive device.
A reel gear is carved in a ring shape at the center of the bottom surface of the reel which emerges from an opening formed in the bottom surface of the magnetic tape cartridge. Due to a driving gear, which is provided at a rotating shaft of the drive device, meshing with the reel gear, the reel is driven to rotate. Further, due to the reel of the magnetic tape cartridge and the take-up reel of the drive device being rotated synchronously, data can be recorded onto the magnetic tape or data recorded on the magnetic tape can be played back.
A large amount of information can be recorded in this magnetic tape cartridge, although little space is needed to accommodate the magnetic tape cartridge when it is stored. As shown in FIGS. 15 through 17, the position of the opening of the magnetic tape cartridge and the type of door for opening and closing the opening differ in accordance with the type of the leader member. Namely, in the case of a leader pin 110, as shown in FIG. 15, an opening 118 is formed in a side wall 114 of a case 112 which side wall 114 is parallel to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow P). The opening 118 is opened and closed by a door 116 which slides in the same direction as the loading direction.
However, if the opening 118 is provided at the side wall 114 of the case 112 in this way, the pull-out means of the drive device must pull the leader pin 110 out from the left-right lateral direction of the case 112 (i.e., non-rectilinearly). Thus, space for the pull-out means to move around the case 112 must be ensured in the left-right lateral direction of the case within the drive device, and the mechanism for moving the pull-out means around (i.e., non-rectilinearly) becomes complex. In other words, the drawback arises that the drive device becomes large. Moreover, there is the problem that the path along which a magnetic tape 108 is pulled out becomes long.
Further, in the case of a leader tape 120, as shown in FIG. 16, an opening 128 is formed in a front wall 124 of a case 122 which front wall 124 is orthogonal to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow P). A door 126, which opens and closes the opening 128, is a pivoting-type door which pivots toward the front around a shaft 125 supported in a vicinity of a corner of the case 122. However, if the opening 128 is provided at the front wall 124 of the case 122 in this way, although there is no need for the pull-out means of the drive device to move non-rectilinearly, the door 126 opens over a wide area toward the front. Therefore, space must be ensured within the drive device such that nothing interferes with the door 126 when the opening 128 is to be opened. In short, a drawback arises in that the drive device becomes large.
Moreover, in the case of a leader block 130, as shown in FIG. 17, an opening 138 is formed by diagonally cutting off a corner portion 134 of the front side of the case in the direction of loading the magnetic tape cartridge into the drive device. The opening 138 is opened and closed directly by the leader block 130. However, if the opening 138 is opened and closed by the leader block 130 in this way (namely, if the leader block also functions as the door for opening and closing the opening), a problem arises in that it is easy for the leader block 130 to become scratched or dirtied. Specifically, the leader block 130 fits together with a reel hub 136 of the drive device and forms a portion of the reel hub 136. Thus, if a scratch is formed in or dirt adheres to the leader block 130, even if the scratch or dirt is a scratch or dirt which is not problematic when the leader block 130 is ordinarily used as the door, it may become difficult for the leader block 130 to fit-together with the reel hub 136, and there is the possibility that problems in the moving of the magnetic tape 108 may arise.
Moreover, the leader block 130 is merely anchored at the edge portion of the opening 138. Thus, there is the drawback that, if the magnetic tape cartridge is dropped or the like, it is easy for the leader block 130 to come apart from the opening 138. Further, because the leader block 130 is larger than the leader pin 110, a problem arises in that the number of constraints on the configuration of the case increases. Namely, the leader pin 110, whose function is separate from that of a door, is technically superior to the leader block 130 which also functions as a door.